A lot of credence is given to climate models. However, climate models--at least as far as I understand them--assume to know (or at least approximate) all variables.
Based upon what happened then, compared to what's happening now, this will happen next.
A height model of me, with data taken from ages two through eight and another from eight through 16, would project me as much taller than I am today (since I stopped growing at age 16--the fault of my mother's vertically challenged genes).
A model projection of casualties in the Civil War, taken after 1st Bull Run, Ft. Henry, and Ft. Donelson could never have foreseen the catastrophic losses of life at Shiloh, Antietam, Fredericksburg, Chancellorsville, Gettysburg, Chickamauga, the Wilderness, Spotsylvania Courthouse, or Cold Harbor.
The reason why these model projections would fail is because they do not account for unexpected changes and because they do not assess enough.
Climate is supposed to be about long-term weather/temperature patterns, and we have scientists talking about the last fifty years.
In the life-span of a human, fifty years is admittedly long-term. However, in the life-span of the Earth, it's not even a drop in the bucket.
I've said this many times, but I'll say it again. The most likely culprit for the most recent trend of warming is the same culprit for the warming that brought us out of the last Ice Age. Since that culprit could not have been man, this culprit cannot be man.
This truth sucks only for those who wish to coerce others into living their lives according to a strict "green religion" doctrine that will one day label me a heretic. Fortunately, they will not burn me at the stake, for I will certainly emit many "greenhouse gasses."
By the way, if methane is a greenhouse gas, then I just contributed to global warming.
Oops, I did it again.
And--damn, I've got to take a shower and change my shorts now.